The Colchester Archaeologist 2002 - Colchester Archaeological Trust

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Public buildings destroyed by Boudica? A surprising feature of the wall is that all the bricks in it appear to be in pieces. It is hard to find any brick which looks as if it might be complete. There are two possible explanations for this curious fact. One is that the brick was deliberately broken up, so that it would make a stronger wall. However, considering how much brick is involved, it seems extraordinary that tilers would make thousands of bricks only for their handiwork to be smashed into fragments. The other explanation is that the bricks are in pieces because the material was salvaged from buildings which had to be demolished. However, this explanation also seems flawed, because had the bricks been reused in this way, we might expect to see lumps of earlier mortar adhering to some of them, and this is not generally the case. A few do indeed seem to have bits of attached earlier mortar, but there is so little of it that the brick fragments must have been extremely well cleaned if indeed they were reused. Thus, although neither explanation can be claimed to be entirely convincing, reuse of the bricks seems by the far the likeliest explanation, and the question then arises as to which buildings the brick came from. Very few houses had brick and stone walls in the 1st century in Colchester. In fact, even in the 2nd and 3rd centuries, when the use of stone and brick was at its peak in domestic construction, most new house walls were generally made out of a kind of mud brick rather than the kiln-fired bricks in the town wall. The only source of brick in the quantities needed for the town wall must have been public buildings. And even then, the scale of the buildings must have been monumental. There was enough brick in the town wall to have made six brick walls, 0.8 metres wide and 4 metres high, across the width of the largest of the squares (insulae) in the town (ie Insulas 22 and 30). Given that, like the town wall, the walls of these buildings would have been made out of a mixture of brick and stone, it is clear that several very large public buildings must have been demolished to produce all the broken brick for the town wall. What might the buildings have been? The most obvious candidates are public baths (probably legionary in origin), a basilica (an aislea hall) opposite the Temple of Claudius, the superstructure of the Temple of Claudius if it needed to be rebuilt, and a monumental colonnade around the temple. The wall was not raised as one unit all round its circuit, but instead was built in sections by a number of gangs each working at their own speed and, to a limited degree, building them in their own way. A close inspection of the bestreserved parts of the wall by the Balkerne Gate has provided evidence of as many as five different sections of wall, and indications of several gangs in operation. The coursing is one indicator. The coursing of the brick and stone forming the sides of the Balkerne Gate does not match the coursing in the adjacent sections of wall to the north and south, apart from at the base. These discontinuities show that the gate and the wall were constructed as one until the work had reached a few feet in height, when the gate was raised more quickly. There are also differences in the fabric of the wall which suggest different gangs with slightly different working practices. The wall on the north side of the gate differs from elsewhere in that it contains thousands of waste chippings Above: plan showing the probable extent of the different sections of wall in which the wall at Balkerne Lane was built. Left: drawing of the junction (Joint A) of the north side of the Balkerne Gate and the adjacent section of town wall. The break in the coursing of the brick and stone shows that the wall and the gate were built independently of each other except for the lowest four courses. A section at a time 20 Reconstruction of the Balkerne Gate by Scout Design showing the gate as it might look today had it survived complete, with the modern buildings behind it. The double arch part in the centre is the triumphal arch, which was incorporated into the new gate in circa AD 70-85.
left over from the dressing of the facing stones. The gate too is different, in that it was bonded with pink mortar (opus signinum) rather than the normal white. (The pink colour is due to the addition of crushed and powdered brick.) Evidence from past excavations elsewhere on the wall circuit helps to fill in a picture of how these gangs operated. Each gang seems to have had its own stockpile of materials close at hand. They dressed the stone and mixed the mortar on wooden boards next to the section of wall that they were building. At the Balkerne Gate, the average length of each unit of wall seems to be about 40-60 m, which would mean that there might be 50 to 75 such sections round the circuit of the wall as a whole. If the wall was built very quickly in one season or so, then the scale of the project would be such that it might have been undertaken by a Roman legion (ie about 5,000 men). However, if the brick in the wall is indeed reused, then the building works probably went on for many years, and their progress must have depended to an extent on the rate at which public buildings were being demolished. The Trust is indebted to Colchester Museums and the Colchester Borough Council for funding the Trust's recent review of the town wall. The purpose of the project was to compile an archive report covering all the archaeological investigations and records relating to the wall over the last fifteen years, including the drawn survey at 1:20 which the Trust carried out some years ago. The latter was undertaken with the aid of grants from English Heritage and Colchester Borough Council as part of a wider programme of works to repair and conserve the wall. PC Below: photo, of a section of wall by the Balkerne Gate in 2001. The search for the town gates of Roman Colchester Compared with some other former Roman towns in Britain, Colchester is fortunate to have the remains of two of its Roman gates still exposed. One of them, the Balkerne Gate, is so well preserved that you can walk under one of its arches, and the other, Duncan's Gate, is sufficiently intact for the lower part of the gate to be completely exposed and on view (in Castle Park). But there were four other Roman gates, and the size and layouts of these gates are not known. This is because, unlike the Balkerne Gate and Duncan's Gate, these gates were in use in the medieval period, and they have since been removed because of decay and road improvement schemes. However, parts or these gates should survive below ground. Certainly small parts of the east sides of Head Gate and the north gate have been observed less than a foot under the surfaces of the modern pavements, and the level of the town wall near St Botolph's Street indicates that the base and foundations of the south gate should be similarly preserved. (The east gate may be exceptional, because it might have been completely destroyed when the gradient or East Hill was reduced in the 19th century.) Opportunities to dig holes on the sites of the missing gates are limited, for obvious reasons, so it was decided to see if it might be possible to detect the presence of any remains by geophysics. Resistivity is no good where the surface is concrete, and magnetometry is not very effective with metal in the vicinity. Our only choice was ground radar. But the sites of all four gates lie under main roads into town, so to carry out a ground-radar survey presented a considerable challenge. Clearly, there had to be as little traffic as possible, and night revellers are best avoided. This left no choice: the survey would have to be done early on a Sunday morning. Above: the ground-radar team working on the site of East Gate, East Hill. Five o'clock seemed to be the time to start. Traffic starts to build up by ten, so that was the deadline for completion. The police were consulted and their permission obtained, and so too the Borough's own traffic control officers. We had flashing lights, as did the ground-radar machine; we had two men at work' signs; we wore luminous jackets; and a risk assessment was prepared. The plan of action was carefully worked out beforehand. Precision timing was vital if we were to finish all four gates before the traffic beat us. Howard. Stephen and I marked out the arias using chalk and strings as guidelines. The grids consisted of lines, spaced at one-metre intervals over the sites of each of the gates. We stretched strings temporarily across the full width of the streets as the lines were chalked. Oncoming traffic was always a problem and a worry. Peter and John worked the ground-radar machine, and Tim carried out a back-up survey using a magnetometer. The grid team started about half an hour before the others to keep ahead. 21
Page 2 and 3: With thanks to all the contributors
Page 4 and 5: Open day at St Botolph's priory and
Page 6 and 7: A British farm under the Romans 200
Page 8 and 9: Above: lines were paint-sprayed on
Page 10 and 11: New light on Colchester Castle A su
Page 12 and 13: William Wire's diary - 5th May 1848
Page 14 and 15: Above: cremation pot with lid. Righ
Page 16 and 17: ecognised by their iron collars. Bu
Page 18 and 19: The Victorian workhouse Andrew Phil
Page 20 and 21: Water supply in Roman Colchester Wa
Page 24 and 25: 'Geophys' at Colchester Geophysics
Page 26 and 27: St John's Abbey explored The precin
Page 28 and 29: Above: a column of reused stone fra
Page 30 and 31: 'W' is for... James Fawn explores t
Page 32 and 33: Play the left luggage game and win
Page 34 and 35: The Friends of Colchester Archaeolo

The Colchester Archaeologist 2002 - Colchester Archaeological Trust

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